A mate of mine being a chippie has made a weapons & kit cupboard out of MDF & has done it a way that it blends in with all the furniture

He's done it in an alcove and has disguised the front as a normal display cupboard so you can't see any evidence of the alcove

As I don't have the room in my bedroom, I've got 2 cupboards with a work bench between them, all the small items go under the lowest drawer in both cupboards & rifles, bags & other large items are under my bed so I have it on wheels to roll out

Cupboard above the stairs in the spare room has a lock. So guns go in their bags and my plate carrier in there. If I had kids and I no longer had a spare room for office/library/armoury I would build a lockable container in my shed that would be screwed to the wall or I have ideas for a box that would fit under the bed.

I have a chest of drawers that contains most of the rest of my stuff, ammo, radios spare pouches.

All my kids are grown up so don't have problems with them, eldest being 29 to youngest being 18 so I'm safe from that, but guns kept in a gun case and kit like others either in a wardrobe or a large kit bag for helmet gloves rig gas ammo etc